Morphology Data of Rhinobatos ranongensis
Identification keys
Main Ref. Last, P.R., B. Séret and G.J.P. Naylor, 2019
Appearance refers to
Bones in OsteoBase

Sex attributes

Specialized organs
Different appearance
Different colors

Descriptive characteristics of juvenile and adult

Striking features
Body shape lateral
Cross section flattened
Dorsal head profile
Type of eyes
Type of mouth/snout
Position of mouth
Type of scales

This medium-sized species is distinguished by the following set of characters in adult male: disc is wedge-shaped and relatively narrow, its width 31-33% TL, length 1.3-1.4 times width; snout moderately elongate, its length 3.0–3.2 times interspiracular distance, 4.1-4.4 times interorbital width; orbit and spiracular openings are small, orbit diameter ~1.5 times spiracle length; nostrils weakly oblique, length 1.3-1.6 times internarial distance; mouth narrow, 5.4-6.0% TL; preoral length 6.3-6.9 times internarial distance; posterior nasal flaps are broad; spiracular folds 2, the outermost fold slightly taller than inner fold; ridges of rostral cartilage are almost parallel, converging anteriorly but not constricted medially; anterior cartilage is broadly sickle shaped, truncate posteriorly; gill slits and their interspaces are narrow, distance between fifth gill slits 3.0-3.2 times in ventral head length; prebranchial sensory pore system distinct, extending to just behind margin of first gill slit; postscapular sensory canal indistinct, deeply embedded, not forming shallow groove; thorn patches present on supraorbit and scapular region, and row along dorsal midline rudimentary, inconspicuous; denticles on dorsal fins are densest anteriorly, present but more sparse posteriorly; dorsal fins are small, height of first 5.4-6.2% TL; pelvic-fin inner margin subequal to its base length; interdorsal distance 2.9-3.3 times first dorsal-fin base; dorsal caudal margin 2.0-2.4 times the preventral margin; upper jaw with 68-82 tooth rows; snout angle 59-64°; pectoral radials 64-68; post-synarcual centra 172-176; nasal lamellae 47-48. Colouration: dorsal fins brownish anteriorly, dusky posteriorly; dorsal disc of adults largely uniformly brownish, no spots or obvious blotches; no large, black, teardrop marking on undersurface of snout (Ref. 123963)

Ease of Identification

Meristic characteristics of Rhinobatos ranongensis

Lateral Lines Interrupted: No
Scales on lateral line
Pored lateral line scales
Scales in lateral series
Scale rows above lateral line
Scale rows below lateral line
Scales around caudal peduncle
Gill clefts (sharks/rays only)
Gill rakers
on lower limb
on upper limb


Dorsal fin(s)

Fins number
Finlets No. Dorsal   
Spines total
Soft-rays total
Adipose fin

Caudal fin


Anal fin(s)

Fins number
Spines total
Soft-rays total

Paired fins

Pectoral Attributes  
Pelvics Attributes  
Main Ref. (e.g. 9948)
Glossary ( e.g. cephalopods )
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